Publications by Alexis Roche | EPFL Graph Search

Related publications (25)

Micro-Structural Brain Alterations in Aviremic HIV+ Patients with Minor Neurocognitive Disorders: A Multi-Contrast Study at High Field

Reto Meuli, Tobias Kober, Alessandro Daducci, Cristina Granziera, Gunnar Krüger, François Lazeyras, Djalel Eddine Meskaldji, Alexis Roche

Objective Mild neurocognitive disorders (MND) affect a subset of HIV+ patients under effective combination antiretroviral therapy (cART). In this study, we used an innovative multi-contrast magnetic resonance imaging (MRI) approach at high-field to assess ...

Public Library of Science2013

Structural abnormalities in the thalamus of migraineurs with aura: a multiparametric study at 3T

Alessandro Daducci, Gunnar Krüger, Cristina Granziera, Nouchine Hadjikhani, David Paul Roger Romascano, Alexis Roche

Background and objectives: The thalamus exerts a pivotal role in pain processing and cortical excitability control, and migraine is characterized by repeated pain attacks and abnormal cortical habituation to excitatory stimuli. This work aimed at studying ...

Wiley-Blackwell2013

Multicontrast MRI Quantification of Focal Inflammation and Degeneration in Multiple Sclerosis

Jean-Philippe Thiran, Cristina Granziera, Gunnar Krüger, Djalel Eddine Meskaldji, Gloria Menegaz, David Paul Roger Romascano, Alexis Roche, Guillaume Bonnier, Ying-Chia Lin

Introduction. Local microstructural pathology in multiple sclerosis patients might influence their clinical performance. This study applied multicontrast MRI to quantify inflammation and neurodegeneration in MS lesions. We explored the impact of MRI-based ...

Hindawi Publishing Corporation2015

Robust T1-Weighted Structural Brain Imaging and Morphometry at 7T Using MP2RAGE

Tobias Kober, Patric Hagmann, José Pedro Rebelo Ferreira Marques, Gunnar Krüger, François Lazeyras, Alexis Roche, Kieran O'Brien

Purpose To suppress the noise, by sacrificing some of the signal homogeneity for numerical stability, in uniform T1 weighted (T1w) images obtained with the magnetization prepared 2 rapid gradient echoes sequence (MP2RAGE) and to compare the clinical utilit ...

Public Library of Science2014

An Ultra-High Field Study of Cerebellar Pathology in Early Relapsing-Remitting Multiple Sclerosis Using MP2RAGE

Tobias Kober, Meritxell Bach Cuadra, Cristina Granziera, Gunnar Krüger, Alexis Roche, Guillaume Bonnier, Kieran O'Brien, Pavel Falkovskiy

Objectives: The aim of this study was to study focal cerebellar pathology in early stages of multiple sclerosis (MS) using ultra-high-field magnetization-prepared 2 inversion-contrast rapid gradient-echo (7T MP2RAGE). Materials and Methods: Twenty early-st ...

Lippincott, Williams & Wilkins2017

Multicontrast connectometry: A new tool to assess cerebellum alterations in early relapsing‐remitting multiple sclerosis

Jean-Philippe Thiran, Dimitri Nestor Alice Van De Ville, Alessandro Daducci, Gunnar Krüger, Djalel Eddine Meskaldji, Gloria Menegaz, Cristina Granziera, David Paul Roger Romascano, Alexis Roche, Jonas Richiardi, Ying-Chia Lin, Guillaume Bonnier

Background: Cerebellar pathology occurs in late multiple sclerosis (MS) but little is known about cerebellar changes during early disease stages. In this study, we propose a new multicontrast “connectometry” approach to assess the structural and functional ...

Wiley-Blackwell2015

A Multi-Contrast MRI Study of Microstructural Brain Damage in Patients with Mild Cognitive Impairment

Meritxell Bach Cuadra, Reto Meuli, Alessandro Daducci, Cristina Granziera, Daniel Andreas Schmitter, Alexis Roche, Guillaume Bonnier

Objectives: The aim of this study was to investigate pathological mechanisms underlying brain tissue alterations in mild cognitive impairment (MCI) using multi-contrast 3 T magnetic resonance imaging (MRI). Methods: Forty-two MCI patients and 77 healthy co ...

Elsevier2015

Migraineurs without aura show microstructural abnormalities in the cerebellum and frontal lobe

Alessandro Daducci, Gunnar Krüger, Cristina Granziera, Nouchine Hadjikhani, David Paul Roger Romascano, Alexis Roche

The involvement of the cerebellum in migraine pathophysiology is not well understood. We used a biparametric approach at high-field MRI (3 T) to assess the structural integrity of the cerebellum in 15 migraineurs with aura (MWA), 23 migraineurs without aur ...

Springer US2013

Cerebellar Connectomics Provide New Biomarkers in Early Multiple Sclerosis

Jean-Philippe Thiran, Dimitri Nestor Alice Van De Ville, Alessandro Daducci, Cristina Granziera, Gunnar Krüger, Djalel Eddine Meskaldji, Jonas Richiardi, Gloria Menegaz, David Paul Roger Romascano, Alexis Roche, Guillaume Bonnier, Ying-Chia Lin

The cerebellum is involved in multiple sclerosis (MS), but its implication in early phases is still poorly understood. We investigated structural and functional cerebellar connectivity alterations in early and minimally impaired MS patients, and their corr ...

2014

On the Convergence of EM-Like Algorithms for Image Segmentation using Markov Random Fields

Meritxell Bach Cuadra, Gunnar Krüger, Alexis Roche, Delphine Ribes Lemay

Inference of Markov random field images segmentation models is usually performed using iterative methods which adapt the well-known expectation-maximization (EM) algorithm for independent mixture models. However, some of these adaptations are ad-hoc and ma ...

2011

Evaluating anorexia-related brain atrophy using MP2RAGE-based morphometry

Tobias Kober, Bénédicte Marie Maréchal, Alexis Roche, François Lazeyras

To evaluate brain atrophy in anorexic patients by automated cerebral segmentation with the magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) MRI sequence. Twenty patients (female; mean age, 27.9 years), presenting consecutively for brain M ...

Springer2017

Volume-based vs. voxel-based brain morphometry in Alzheimer's disease prediction

Meritxell Bach Cuadra, Alessandro Daducci, Reto Meuli, Gunnar Krüger, Bénédicte Marie Maréchal, Cristina Granziera, Alexis Roche, Delphine Ribes Lemay, Daniel Andreas Schmitter

Voxel-based morphometry from conventional T1-weighted images has proved effective to quantify Alzheimer's disease (AD) related brain atrophy and to enable accurate automated classification of AD patients, mild cognitive impaired (MCI) patients and elderly ...

Proceedings of 23rd International Society for Magnetic Resonance in Medicine (ISMRM) Conference2014

Comparison of accelerated T1-weighted whole-brain structural-imaging protocols

Jean-Philippe Thiran, Reto Meuli, Tobias Kober, Bénédicte Marie Maréchal, Alexis Roche, Pavel Falkovskiy

Imaging in neuroscience, clinical research and pharmaceutical trials often employs the 3D magnetisation-prepared rapid gradient-echo (MPRAGE) sequence to obtain structural T1-weighted images with high spatial resolution of the human brain. Typical research ...

Academic Press Inc Elsevier Science2016

Multiple Sclerosis Lesion Fingerprint Using Multicontrast MRI

Jean-Philippe Thiran, Cristina Granziera, Gunnar Krüger, Djalel Eddine Meskaldji, Gloria Menegaz, David Paul Roger Romascano, Alexis Roche, Guillaume Bonnier, Ying-Chia Lin

Conventional magnetic resonance imaging (MRI) measures of multiple sclerosis patients provide limited information about the nature and the extent of brain damage and repair. We established a clinically compatible protocol including quantitative MRI techniq ...

2014

Multicontrats MRI Improved the Clinico-Radiological Correlation in Early Multiple Sclerosis Patients with Minor Deficits

Jean-Philippe Thiran, Cristina Granziera, Gunnar Krüger, Djalel Eddine Meskaldji, Gloria Menegaz, David Paul Roger Romascano, Alexis Roche, Guillaume Bonnier, Ying-Chia Lin

Conventional magnetic resonance imaging (MRI) of patients with multiple sclerosis provides only limited insights into the nature of brain tissue damage with modest clinical-radiological correlations. In this study, quantitative and semi-quantitative MRI te ...

2014

Microstructural alterations in the brain of well treated HIV+ patients with minor neurocognitive disorders: a multi-contrast MRI study at 3T

Alessandro Daducci, Cristina Granziera, Gunnar Krüger, Djalel Eddine Meskaldji, Alexis Roche

2012

An evaluation of volume-based morphometry for prediction of mild cognitive impairment and Alzheimer's disease

Reto Meuli, Meritxell Bach Cuadra, Alessandro Daducci, Gunnar Krüger, Cristina Granziera, Bénédicte Marie Maréchal, Daniel Andreas Schmitter, Alexis Roche, Delphine Ribes Lemay

Voxel-based morphometry from conventional T1-weighted images has proved effective to quantify Alzheimer’s disease (AD) related brain atrophy and to enable fairly accurate automated classification of AD patients, mild cognitive impaired patients (MCI) and e ...

Elsevier2015

A simple method to denoise ratio images in magnetic resonance imaging

Alexis Roche, Kieran O'Brien

Disclosed is a Magnetic Resonance Imaging method comprising the steps of: generating an MRI sequence designed for acquiring data from an object to be imaged, wherein the MRI sequence is configured for generating at least two different standard images, resp ...

2014

Structural abnormalities in the thalamus of migraine patients: a multi-parametric study at high field

Alessandro Daducci, Gunnar Krüger, Cristina Granziera, Nouchine Hadjikhani, David Paul Roger Romascano, Alexis Roche

2012

Personalized pathology maps to quantify diffuse and focal brain damage

Tobias Kober, Cristina Granziera, Tom Hilbert, Alexis Roche, Elda Fischi Gomez, Guillaume Bonnier

2019